Zinc flake coatings protect metal components used in the automotive industry from corrosion. During series production, time-consuming corrosion testing is necessary to assure coating quality, and this can take up to three months. This leads to costly delays in recognizing changes in coating quality and identifying the necessary corrective measures. The Steinbeis Transfer Center for Corrosion and Corrosion Prevention, located in Friedrichshafen and at the Ravensburg-Weingarten University of Applied Sciences, teamed up with Daimler AG, Holder GmbH Oberflächentechnik and Ingenieurbüro Peter Schrems (IPS) to develop an innovative testing method for accelerating the assessment of zinc flake coatings and their capacity to prevent corrosion.
Short-term testing involves subjecting a component to voltage in a measuring cell to simulate corrosion stress during operation. The course of the test signal is quality-specifi c and can be supplemented with other analytical methods of evaluation as needed. Thanks to a new, stand-alone potentiostat developed by IPS and the Steinbeis team, featuring software that automatically analyzes measurement results, companies will no longer require specialist staff to interpret data. The method was proven effective under laboratory conditions set up in cooperation between the coating specialists at Holder and Daimler, which tested a standard zinc fl ake coating. Reliable and reproducible results were available just four hours after testing began. These results will make it possible to react much more quickly to changes in quality, as well as initiate necessary corrective measures. Due to a higher measurement rate, processes can be executed in a smaller window of time, reducing costs for time-intensive testing during series production. The most recent challenge is to implement this method in running production processes using a measuring cell attached directly to the component. The method, awarded with the Steinbeis Foundation’s Transfer Award – Lohn Award, is sure to unleash tremendous potential for application in quality management for other coating processes and surface technologies once the necessary modifi cations have been made.
Prof. Dr.-Ing. Reinhold Holbein
Steinbeis Transfer Center Corrosion and Corrosion Prevention (Friedrichshafen)